MicroElectroMechanical System (MEMS) devices include microphones and receivers to mention two examples. In these devices, different electrical components are disposed together within a housing unit. For example, a receiver typically includes a coil, magnets, and stack, among other components and these components are housed within the receiver assembly. Other types of acoustic devices may include other types of components.
Acoustic devices sometimes include integrated circuits such as application specific integrated circuit (ASICs). Often, these devices need to be programmed. Programming is typically accomplished by the use of external pads that are often located on the bottom of a MEMS device. These pads couple to the integrated circuit through conductive traces or other conductive members passing through the substrate. To program a device, a user usually couples a programming device to these pads, and then programs the integrated circuit. Once the programming is accomplished, the user simply removes the device.
There are some problems associated with these previous approaches. It is typically not desirable to allow the device to be re-programmed after the initial programming is accomplished. In this case, an unauthorized user might simply connect another programming device to the pads, and then re-program the device. Unauthorized programming of an ASIC, for example, may cause the ASIC to function improperly and, in fact, may prevent the entire MEMS device from functioning properly. This, in turn, may have consequences that range from minor performance issues concerning the degradation of system performance to safety issues when the MEMS device is disposed in a critical piece of electronic equipment.
Previous systems and approaches have not provided a way to adequately prevent the unauthorized re-programming of integrated circuits in MEMS devices. In fact, previous systems and approaches are completely silent as to overcoming these problems.
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